------------[ cut here ]------------ kernel BUG at mm/khugepaged.c:469! invalid opcode: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 8800 Comm: syz-executor.2 Not tainted 5.8.0-next-20200812-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__khugepaged_enter+0x306/0x3d0 mm/khugepaged.c:469 Code: e4 49 81 fe 60 bd d2 89 74 2a e8 d5 61 bb ff 44 89 e0 5b 5d 41 5c 41 5d 41 5e 41 5f c3 e8 c2 61 bb ff 48 89 ef e8 9a bf e9 ff <0f> 0b 41 bc f4 ff ff ff eb d6 e8 ab 61 bb ff 31 c9 ba 01 00 00 00 RSP: 0018:ffffc90005687930 EFLAGS: 00010282 RAX: 000000000000036a RBX: 0000000000000003 RCX: 0000000000000000 RDX: 0000000000040000 RSI: ffffffff815da8f7 RDI: fffff52000ad0ec5 RBP: ffff8880a1153140 R08: 000000000000036a R09: ffff8880ae6318e7 R10: 0000000000000000 R11: 00000000000cead8 R12: ffff8880a977d0b0 R13: ffff8880a115319c R14: 0000000020000000 R15: ffffc90005687a68 FS: 00007f110d246700(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000016a3b73 CR3: 000000009388e000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: khugepaged_enter include/linux/khugepaged.h:62 [inline] do_huge_pmd_anonymous_page+0xaa1/0x2230 mm/huge_memory.c:707 create_huge_pmd mm/memory.c:4108 [inline] __handle_mm_fault mm/memory.c:4335 [inline] handle_mm_fault+0x36dd/0x45e0 mm/memory.c:4462 do_user_addr_fault+0x598/0xbf0 arch/x86/mm/fault.c:1294 handle_page_fault arch/x86/mm/fault.c:1351 [inline] exc_page_fault+0xa8/0x160 arch/x86/mm/fault.c:1404 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:538 RIP: 0010:copy_user_enhanced_fast_string+0xe/0x30 arch/x86/lib/copy_user_64.S:205 Code: 89 d1 c1 e9 03 83 e2 07 f3 48 a5 89 d1 f3 a4 31 c0 0f 1f 00 c3 0f 1f 80 00 00 00 00 0f 1f 00 83 fa 40 0f 82 70 ff ff ff 89 d1 a4 31 c0 0f 1f 00 c3 66 2e 0f 1f 84 00 00 00 00 00 89 d1 f3 a4 RSP: 0018:ffffc90005687c78 EFLAGS: 00010206 RAX: 0000000000000001 RBX: 0000000020000000 RCX: 000000000000006b RDX: 000000000000006b RSI: ffff88808fc5a800 RDI: 0000000020000000 RBP: ffff88808fc5a800 R08: 0000000000000000 R09: ffff88808fc5a86a R10: ffffed1011f8b50d R11: 0000000000000000 R12: 000000000000006b R13: 000000002000006b R14: 00007ffffffff000 R15: 0000000000000000 copy_user_generic arch/x86/include/asm/uaccess_64.h:37 [inline] raw_copy_to_user arch/x86/include/asm/uaccess_64.h:58 [inline] _copy_to_user+0x11e/0x160 lib/usercopy.c:30 copy_to_user include/linux/uaccess.h:168 [inline] syslog_print_all+0x34c/0x590 kernel/printk/printk.c:1545 do_syslog.part.0+0x3ff/0x8d0 kernel/printk/printk.c:1610 do_syslog kernel/printk/printk.c:1682 [inline] __do_sys_syslog kernel/printk/printk.c:1684 [inline] __se_sys_syslog kernel/printk/printk.c:1682 [inline] __x64_sys_syslog+0x97/0xc0 kernel/printk/printk.c:1682 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45d249 Code: 5d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 2b b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f110d245c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000067 RAX: ffffffffffffffda RBX: 0000000000032f00 RCX: 000000000045d249 RDX: 00000000000000ce RSI: 0000000020000000 RDI: 0000000000000003 RBP: 000000000118cf80 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cf4c R13: 00007fff48dc66df R14: 00007f110d2469c0 R15: 000000000118cf4c Modules linked in: ---[ end trace 077d6b4335cb23ae ]--- RIP: 0010:__khugepaged_enter+0x306/0x3d0 mm/khugepaged.c:469 Code: e4 49 81 fe 60 bd d2 89 74 2a e8 d5 61 bb ff 44 89 e0 5b 5d 41 5c 41 5d 41 5e 41 5f c3 e8 c2 61 bb ff 48 89 ef e8 9a bf e9 ff <0f> 0b 41 bc f4 ff ff ff eb d6 e8 ab 61 bb ff 31 c9 ba 01 00 00 00 RSP: 0018:ffffc90005687930 EFLAGS: 00010282 RAX: 000000000000036a RBX: 0000000000000003 RCX: 0000000000000000 RDX: 0000000000040000 RSI: ffffffff815da8f7 RDI: fffff52000ad0ec5 RBP: ffff8880a1153140 R08: 000000000000036a R09: ffff8880ae6318e7 R10: 0000000000000000 R11: 00000000000cead8 R12: ffff8880a977d0b0 R13: ffff8880a115319c R14: 0000000020000000 R15: ffffc90005687a68 FS: 00007f110d246700(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2be22000 CR3: 000000009388e000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400